Abstract

Resistance measurements in pulsed magnetic fields up to 55 T as well as a first-principles DFT calculation of the Fermi surface for the organic metal (TSeT)2Cl have been performed to investigate its metal-semimetal phase transition. The results obtained are in line with the imperfect nesting that can be inferred from both the observed metallic behavior of the resistivity at low temperature and the previously reported Shubnikov-de Haas oscillations due to small carrier pockets. The DFT study points out the possibility that the LUMO bands of the TSeT donor may interact with the HOMO ones and modify the shape of the Fermi surface under pressure.

C. W. Mayer and B. Hilti are thanked for providing crystals of (TSeT)2Cl around twenty years ago which have been used in our measurements. We are grateful to M.-L. Doublet for communication of results. This work was supported by DGI-Spain (Grant Nos. CSD2007-00041, FIS2012-37549- C05-05, and CTQ2011-23862-C02-02), Generalitat de Catalunya (2009 SGR 1459) and XRQTC. Part of this work has been supported by EuroMagNET II under EU Contract No. 228043.